2 * Copyright (c) 2021 Samsung Electronics Co., Ltd.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
18 #include <dali/internal/imaging/common/loader-png.h>
25 #include <dali/devel-api/adaptor-framework/pixel-buffer.h>
26 #include <dali/integration-api/debug.h>
27 #include <dali/internal/legacy/tizen/platform-capabilities.h>
31 namespace TizenPlatform
35 // simple class to enforce clean-up of PNG structures
38 auto_png(png_structp& _png, png_infop& _info)
48 png_destroy_read_struct(&png, &info, NULL);
54 }; // struct auto_png;
56 bool LoadPngHeader(FILE* fp, unsigned int& width, unsigned int& height, png_structp& png, png_infop& info)
58 png_byte header[8] = {0};
60 // Check header to see if it is a PNG file
61 size_t size = fread(header, 1, 8, fp);
64 DALI_LOG_ERROR("fread failed\n");
68 if(png_sig_cmp(header, 0, 8))
70 DALI_LOG_ERROR("png_sig_cmp failed\n");
74 png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
78 DALI_LOG_ERROR("Can't create PNG read structure\n");
82 info = png_create_info_struct(png);
85 DALI_LOG_ERROR("png_create_info_struct failed\n");
91 if(setjmp(png_jmpbuf(png)))
93 DALI_LOG_ERROR("error during png_init_io\n");
98 png_set_sig_bytes(png, 8);
101 png_read_info(png, info);
104 width = png_get_image_width(png, info);
105 height = png_get_image_height(png, info);
112 bool LoadPngHeader(const Dali::ImageLoader::Input& input, unsigned int& width, unsigned int& height)
114 png_structp png = NULL;
115 png_infop info = NULL;
116 auto_png autoPng(png, info);
118 bool success = LoadPngHeader(input.file, width, height, png, info);
123 bool LoadBitmapFromPng(const Dali::ImageLoader::Input& input, Dali::Devel::PixelBuffer& bitmap)
125 png_structp png = NULL;
126 png_infop info = NULL;
127 auto_png autoPng(png, info);
129 /// @todo: consider parameters
131 unsigned int width, height;
133 unsigned int bpp = 0; // bytes per pixel
136 // Load info from the header
137 if(!LoadPngHeader(input.file, width, height, png, info))
142 Pixel::Format pixelFormat = Pixel::RGBA8888;
144 // decide pixel format
145 unsigned int colordepth = png_get_bit_depth(png, info);
147 // Ask PNGLib to convert high precision images into something we can use:
150 png_set_strip_16(png);
154 png_byte colortype = png_get_color_type(png, info);
156 if(colortype == PNG_COLOR_TYPE_GRAY ||
157 colortype == PNG_COLOR_TYPE_GRAY_ALPHA)
159 if(colortype == PNG_COLOR_TYPE_GRAY)
161 pixelFormat = Pixel::L8;
162 if(png_get_valid(png, info, PNG_INFO_tRNS))
164 colortype = PNG_COLOR_TYPE_GRAY_ALPHA;
165 /* expand transparency entry -> alpha channel if present */
166 png_set_tRNS_to_alpha(png);
167 pixelFormat = Pixel::LA88;
172 pixelFormat = Pixel::LA88;
177 /* expand gray (w/reduced bits) -> 8-bit RGB if necessary */
178 png_set_expand_gray_1_2_4_to_8(png);
179 /* pack all pixels to byte boundaries */
180 png_set_packing(png);
184 else if(colortype == PNG_COLOR_TYPE_RGB)
190 pixelFormat = Pixel::RGB888;
194 case 5: /// @todo is this correct for RGB16 5-6-5 ?
196 pixelFormat = Pixel::RGB565;
206 else if(colortype == PNG_COLOR_TYPE_RGBA)
212 pixelFormat = Pixel::RGBA8888;
222 else if(colortype == PNG_COLOR_TYPE_PALETTE)
228 pixelFormat = Pixel::LA88;
237 /* Expand paletted or RGB images with transparency to full alpha channels
238 * so the data will be available as RGBA quartets. PNG_INFO_tRNS = 0x10
240 if(png_get_valid(png, info, PNG_INFO_tRNS) == 0x10)
242 pixelFormat = Pixel::RGBA8888;
247 pixelFormat = Pixel::RGB888;
248 png_set_packing(png);
249 png_set_packswap(png);
250 png_set_palette_to_rgb(png);
264 DALI_LOG_ERROR("Unsupported png format\n");
269 bpp = Pixel::GetBytesPerPixel(pixelFormat);
271 png_read_update_info(png, info);
273 if(setjmp(png_jmpbuf(png)))
275 DALI_LOG_ERROR("error during png_read_image\n");
279 unsigned int rowBytes = png_get_rowbytes(png, info);
281 unsigned int bufferWidth = GetTextureDimension(width);
282 unsigned int bufferHeight = GetTextureDimension(height);
283 unsigned int stride = bufferWidth * bpp;
285 // not sure if this ever happens
286 if(rowBytes > stride)
288 stride = GetTextureDimension(rowBytes);
290 bpp = stride / bufferWidth;
294 pixelFormat = Pixel::RGB888;
297 pixelFormat = Pixel::RGBA8888;
304 // decode the whole image into bitmap buffer
305 auto pixels = (bitmap = Dali::Devel::PixelBuffer::New(bufferWidth, bufferHeight, pixelFormat)).GetBuffer();
307 DALI_ASSERT_DEBUG(pixels);
308 rows = reinterpret_cast<png_bytep*>(malloc(sizeof(png_bytep) * height));
311 DALI_LOG_ERROR("malloc is failed\n");
315 for(y = 0; y < height; y++)
317 rows[y] = pixels + y * stride;
321 png_read_image(png, rows);
328 // simple class to enforce clean-up of PNG structures
331 AutoPngWrite(png_structp& _png, png_infop& _info)
341 png_destroy_write_struct(&png, &info);
347 }; // struct AutoPngWrite;
351 // Custom libpng write callbacks that buffer to a vector instead of a file:
354 * extern "C" linkage is used because this is a callback that we pass to a C
355 * library which is part of the underlying platform and so potentially compiled
356 * as C rather than C++.
357 * @see http://stackoverflow.com/a/2594222
359 extern "C" void WriteData(png_structp png_ptr, png_bytep data, png_size_t length)
361 DALI_ASSERT_DEBUG(png_ptr && data);
362 if(!png_ptr || !data)
366 // Make sure we don't try to propagate a C++ exception up the call stack of a pure C library:
369 // Recover our buffer for writing into:
370 Vector<unsigned char>* const encoded_img = static_cast<Vector<unsigned char>*>(png_get_io_ptr(png_ptr));
373 const Vector<unsigned char>::SizeType bufferSize = encoded_img->Count();
374 encoded_img->Resize(bufferSize + length); //< Can throw OOM.
375 unsigned char* const bufferBack = encoded_img->Begin() + bufferSize;
376 memcpy(bufferBack, data, length);
380 DALI_LOG_ERROR("PNG buffer for write to memory was passed from libpng as null.\n");
385 DALI_LOG_ERROR("C++ Exception caught\n");
389 /** Override the flush with a NOP to prevent libpng trying cstdlib file io. */
390 extern "C" void FlushData(png_structp png_ptr)
393 Debug::LogMessage(Debug::DebugInfo, "PNG Flush");
394 #endif // DEBUG_ENABLED
399 * Potential improvements:
400 * 1. Detect <= 256 colours and write in palette mode.
401 * 2. Detect grayscale (will early-out quickly for colour images).
402 * 3. Store colour space / gamma correction info related to the device screen?
403 * http://www.libpng.org/pub/png/book/chapter10.html
404 * 4. Refactor with callers to write straight through to disk and save keeping a big buffer around.
405 * 5. Prealloc buffer (reserve) to input size / <A number greater than 2 (expexcted few realloc but without using lots of memory) | 1 (expected zero reallocs but using a lot of memory)>.
406 * 6. Set the modification time with png_set_tIME(png_ptr, info_ptr, mod_time);
407 * 7. If caller asks for no compression, bypass libpng and blat raw data to
408 * disk, topped and tailed with header/tail blocks.
410 bool EncodeToPng(const unsigned char* const pixelBuffer, Vector<unsigned char>& encodedPixels, std::size_t width, std::size_t height, Pixel::Format pixelFormat)
412 // Translate pixel format enum:
413 int pngPixelFormat = -1;
414 unsigned pixelBytes = 0;
415 bool rgbaOrder = true;
417 // Account for RGB versus BGR and presence of alpha in input pixels:
422 pngPixelFormat = PNG_COLOR_TYPE_RGB;
426 case Pixel::BGRA8888:
429 ///! No break: fall through:
431 case Pixel::RGBA8888:
433 pngPixelFormat = PNG_COLOR_TYPE_RGB_ALPHA;
439 DALI_LOG_ERROR("Unsupported pixel format for encoding to PNG.\n");
444 const int interlace = PNG_INTERLACE_NONE;
446 png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
451 /* Allocate/initialize the image information data. REQUIRED */
452 png_infop info_ptr = png_create_info_struct(png_ptr);
455 png_destroy_write_struct(&png_ptr, NULL);
459 /* Set error handling. REQUIRED if you aren't supplying your own
460 * error handling functions in the png_create_write_struct() call.
462 if(setjmp(png_jmpbuf(png_ptr)))
464 png_destroy_write_struct(&png_ptr, &info_ptr);
468 // Since we are going to write to memory instead of a file, lets provide
469 // libpng with a custom write function and ask it to pass back our
470 // Vector buffer each time it calls back to flush data to "file":
471 png_set_write_fn(png_ptr, &encodedPixels, WriteData, FlushData);
473 // png_set_compression_level( png_ptr, Z_BEST_COMPRESSION);
474 png_set_compression_level(png_ptr, Z_BEST_SPEED);
475 // png_set_compression_level( png_ptr, Z_NO_COMPRESSION); //! We could just generate png directly without libpng in this case.
477 // Explicitly limit the number of filters used per scanline to speed us up:
478 // png_set_filter(png_ptr, 0, PNG_FILTER_NONE); ///!ToDo: Try this once baseline profile is in place.
482 // PNG_FILTER_PAETH |
484 // Play with Zlib parameters in optimisation phase:
485 // png_set_compression_mem_level(png_ptr, 8);
486 // png_set_compression_strategy(png_ptr,
487 // Z_DEFAULT_STRATEGY);
488 // png_set_compression_window_bits(png_ptr, 15);
489 // png_set_compression_method(png_ptr, 8);
490 // png_set_compression_buffer_size(png_ptr, 8192)
492 // Let lib_png know if the pixel bytes are in BGR(A) order:
495 png_set_bgr(png_ptr);
498 // Set the image information:
499 png_set_IHDR(png_ptr, info_ptr, width, height, 8, pngPixelFormat, interlace, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
501 // Start to output the PNG data to our buffer:
502 png_write_info(png_ptr, info_ptr);
505 const unsigned row_step = width * pixelBytes;
506 png_bytep row_ptr = const_cast<png_bytep>(pixelBuffer);
507 const png_bytep row_end = row_ptr + height * row_step;
508 for(; row_ptr < row_end; row_ptr += row_step)
510 png_write_row(png_ptr, row_ptr);
513 /* It is REQUIRED to call this to finish writing the rest of the file */
514 png_write_end(png_ptr, info_ptr);
515 /* Clean up after the write, and free any memory allocated */
516 png_destroy_write_struct(&png_ptr, &info_ptr);
520 } // namespace TizenPlatform